Internal combustion engines include components such as cylinder blocks and cylinder heads that are often formed using casting, die casting, or other process. These components and their manufacturing techniques often involve extensive development and tooling times and costs.
In certain scenarios, it may be desirable to continue to the use these components while changing the underlying engine configuration, for example, by downsizing the engine to a lower displacement. The downsized engine may use the same carryover block and head with either the same intake manifold or a new intake manifold specifically designed for the smaller engine, and this may result in a loss of engine performance due to a change in combustion characteristics in cylinder.